1. Field of the Invention
The present invention relates to a storage control system and a method of controlling the storage control system.
2. Description of the Related Art
A storage control system is configured by arranging hard disc storage devices and other such storage devices in an array, and, for example, provides a storage area based on RAID (Redundant Array of Independent Disks) to a host computer (hereinafter, may be abbreviated as host). At least one or more logical volumes are formed on a physical storage area provided by a group of storage devices, and this logical volume is provided to a host. A host reads or writes data from or to a logical volume by sending a prescribed command.
Here, a plurality of storage devices are connected via a daisy-chain mode, or via a crossbar switch (Japanese Patent Laid-open No. 2003-303055).
A storage device, for example, may comprise a plurality of types of operating modes. Further, in order to use a storage device, a storage control system must preset in the respective storage devices identification information for specifying each storage device. However, the above-mentioned literature discloses neither a constitution nor a method for setting an operating mode or identification information in the storage devices.
If a failure of some kind should occur in a control circuit for controlling the storage devices, it becomes impossible to set an operating mode or identification information in the storage devices. Consequently, it becomes impossible to operate a storage control system normally, lowering reliability and ease of use. In particular, there has been a trend in recent years to increase the capacity of storage control systems, and the number of storage devices managed by each control circuit is increasing. Therefore, if any one of the control circuits of a plurality of control circuits fails, a large number of storage devices become unusable as a result, causing the adverse affects to become widespread.
In particular, whereas storage control systems are being used for a relatively long number of years, storage device and storage device peripheral technologies are advancing rapidly, promoting generational upgrades. Therefore, there is the likelihood of a plurality of generations of storage devices having different specifications being included inside a storage control system. In order to use storage devices having different specifications like this, the settings of each storage device must be changed. However, the prior art does not give enough consideration to a redundant constitution for changing the settings of the storage devices, leaving room for improvement.